Congenital malformations of the heart and great vessels (hereafter referred to as congenital cardiac malformations) are the most common and the most commonly fatal class of birth defects. Approximately one million Americans have such defects. Annual hospital charges for inpatient procedures performed on patients <18 years of age may now exceed $2.0 billion. This does not necessarily reflect true costs or re-imbursement, and excludes costs of physician care and of some outpatient procedures. What little is known in aggregate about pediatric cardiac surgery and transcatheter interventional cardiology procedures as a whole raises questions such as the following: Do the rates, outcomes and costs of these procedures vary across states or over time? What are the resource use and cost implications of evolving shifts from cardiac surgery to interventional cardiology procedures, and from inpatient to outpatient procedures? Do relationships between institutional volumes and adverse event rates following transcatheter procedures argue for regionalization of this care? Do blacks and whites have similar access to procedures Performed for specific pediatric cardiac conditions? And finally, are administrative data adequate for addressing such issues? We propose a population-based study using existing electronic data to help fill gaps in our knowledge about these procedures. Our study has the following specific aims: 1) To describe admission rates, costs and inpatient mortality for pediatric cardiac surgical and transcatheter procedures performed in eight states from 1999-2003, 2) to assess the relationship between institutional variations in transcatheter procedure volumes and one year adverse event rates; and 3) to compare access to specific cardiac procedures among black and white children. We will achieve these aims in a study combining census data with confidential encounter-level administrative data from Colorado, Florida, Kentucky, North Carolina, Pennsylvania, South Carolina, Tennessee and Utah. These eight states report complete capture of hospital data on outpatient as well as inpatient pediatric cardiac procedures and have in-state referral centers expected to account for almost all cardiac procedures performed on state residents. Individual data elements and coding algorithms will be validated using more detailed clinical information that hospitals in four participating states also provide to the Pediatric Cardiac Care Consortium registry. Uncertainty abounds regarding procedure rates, safety, and quality of care, costs, volume outcome relationships and racial disparities in access to care in many areas of medicine. We will address such concerns in the increasingly important but as yet understudied realm of pediatric cardiac interventions.